rosstart

source /opt/ros/melodic/setup.bash
mkdir -p ~/catkin_ws/src
cd ~/catkin_ws/

catkin build
source devel/setup.bash
cd ~/catkin_ws/src
catkin_create_pkg ninja_turtle rospy roscpp turtlesim geometry_msgs
cd ~/catkin_ws
catkin build
source devel/setup.bash


mkdir ~/catkin_ws/src/ninja_turtle/scripts
curl https://raw.githubusercontent.com/romarcg/ninja_turtle/master/scripts/ninja_turtle_node.py --output  ~/catkin_ws/src/ninja_turtle/scripts/ninja_turtle_node.py

chmod u+x ~/catkin_ws/src/ninja_turtle/scripts/ninja_turtle_node.py